Encapsulating Halometallates into 3-D Lanthanide-Viologen Frameworks: Controllable Emissions, Reversible Thermochromism, Photocurrent Responses, and Electrical Bistability Behaviors

Abstract

The encapsulation of guests into metal−organic frameworks (MOF) is an efficient strategy to generate novel multifunctional materials with enhanced properties. Herein, four halometallate@MOF composites with formulas of {(Pb 2 I 4 Br 3 ) [(Pr(bpdo) [(La(bpdo) 4 (H 2 O) 2 ] 2 } n (4) (bpdo = 4,4′-bipyridine N,N′-dioxide) were prepared. In these composites, lanthanide-viologen MOF act as matrices, whose cavities were penetrated by halometallates. Consequently, the insertion of electron-rich halometallates into electron-deficient lanthanide-viologen matrices leads to the presence of strong room temperature charge transfer (CT) interactions. Importantly, these composites exhibit enhanced photo/thermal stabilities, controllable white emissions, reversible thermochromisms, and good photocurrent response performances. Specially, the memory devices based on these composites illustrate reversible electrical bistability behaviors, which can be assigned to ohmic and space-charge-limited conduction (SCLC) mechanisms. This kind of composite can be utilized as a multifunctional platform with enhanced stability.

Lanthanide-based metal–organic framework materials as bifunctional fluorescence sensors toward acetylacetone and aspartic acid

“…16,17 Therefore, the reaction of lanthanide ions with suitable ligands has become an effective way to construct multifunctional lanthanide-based MOFs (Ln-MOFs). 18,19 In particular, the photoluminescence characteristics of Ln-MOFs expand the application in molecular switches and chemical sensors. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Many Ln-MOFs have been applied to detect metal cations, inorganic anions and small organic molecules.…”

“…18,19 In particular, the photoluminescence characteristics of Ln-MOFs expand the application in molecular switches and chemical sensors. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Many Ln-MOFs have been applied to detect metal cations, inorganic anions and small organic molecules. 25,26 However, there are few reports of Ln-MOFs for the detection of amino acids.…”

Resistive Memory Devices Based on Reticular Materials for Electrical Information Storage

“…Following the memristive mechanism of the ejection and trapping of charges induced by the conversion between Ohmic and SCLC mode, halometallate-embedded MOF film devices displayed bistability and resistive switching characteristics with an ON/OFF ratio of 10 3 . 95 The halometallate-embedded MOFs ({[Pb 3 I 10 (H 2 O) 2 ][Y 2 (bpdo) 5 (OH) 2 ]•4(H 2 O)} n and {(Bi 2 I 9 )[(Pr(bpdo) 3 (H 2 O)]} n ) were synthesized by the solvothermal method in an autoclave. These solutions were spin-coated on a polymer-coated ITO substrate, and then Ag electrodes were deposited to fabricate the memristive device.…”

“…As heterogeneous MOF composite film-based RS devices operated by Ohmic and SCLC mode above-mentioned, 63,95 a kind of MOF thin film itself, mechanically robust [Cu 2 I 2 (TAA)] n film, prepared by the Langmuir-Schafer technique, exhibited memristive behavior presenting pinched hysteresis with an ON/OFF ratio up to 30 and sweeping speeds below 0.3 V/s. 81 Liu et al 59 reported that the ZIF-8 thin film could show nonvolatile resistive switching characteristics with the fabricated sandwiched device structure of Ag/ZIF-8/Si (Figure 7a).…”

Photo-sensitive hybrids constructed from diphenyliodonium and metal-thiocyanates: photo-induced structure and property transformations

“…2,3 Recently, as a photoactive component with strong electron-accepting behaviors, excellent redox characteristics and sensitive photo/thermal chromisms, viologens have been widely used in the construction of functional charge-transfer (CT) complexes, whose electron transfer processes were accompanied by simultaneous generation of free radicals. [4][5][6][7] However, some disadvantages have emerged in viologen-based composite materials, including slow photo-responsibility and reversibility. 4 Therefore, modifications of viologens, including the introduction of π-conjugated substituents as electron donors and stabilizers, have been conducted.…”